Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The site hosts a collection of pay-per-request APIs spanning data & analytics, AI/ML inference, finance & Web3 data, and infrastructure utilities, all priced at $0.02 per request and settled in USDC on the Base network. No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.
The specific endpoint `/api/v1/charges/94` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The payment scheme is "exact" with a 300-second timeout. The endpoint accepts POST requests and returns application/json.
However, the actual functionality behind this particular endpoint (`/charges/94`) is not documented beyond the generic label "Premium API Access." The site's docs, pricing, and README pages all render only a wallet-connect prompt with no substantive documentation. Without an OpenAPI spec, request/response schemas, or usage examples, it is unclear what data or service this specific charge endpoint provides. The broader site advertises endpoints for sentiment analysis, text summarization, embeddings, geocoding, price feeds, and more, but none of those map directly to `/api/v1/charges/94`.
Capabilities
Use cases
- —Agent-initiated API calls with automatic per-request USDC micropayments
- —Accessing premium data or services without API key registration
- —Programmatic pay-as-you-go access from wallets or x402-enabled clients
Fit
Best for
- —Developers wanting zero-signup, pay-per-call API access
- —AI agents with x402-compatible payment capabilities
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-network USDC wallet or x402 client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/94 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect page, and the specific functionality of /api/v1/charges/94 is entirely undocumented. This is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, and README pages all render only a wallet-connect prompt
- —The specific functionality of /api/v1/charges/94 ('Premium API Access') is not described anywhere
- —No OpenAPI spec or request/response schema provided
- —No example requests or responses available to verify what the endpoint actually returns
Citations
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge requests maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with 300s timeouthttps://lowpaymentfee.com/api/v1/charges/94
- —The site lists APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com